(a)The no-arg constructor you are referring to is a explicitly defined substitute to the “default constructor”.If the programmer doesn’t explicitly define a constructor,then the compiler(javac) automatically defines a default constructor as ClassName(){}.This constructor is not visible in the code,however after the compilation is done,it is present in the java bytecode. (b)In your case, there is … Read more
I do not really understand your question. That public class Test3 { private final String test = “test123”; public Test3() { System.out.println(“Test = “+test); } public static void main(String[] args) { Test3 t = new Test3(); } } executes as follows: $ javac Test3.java && java Test3 Test = test123
The syntax X a = b; where a and b are of type X has always meant copy construction. Whatever variants, such as: X a = X(); are used, there is no assignment going on, and never has been. Construct and assign would be something like: X a; a = X();
The most derived class initializes any virtual base classes. In your class hierarchy, Unknown must construct the virtual Animal base class (e.g. by adding Animal(a) to its initialization list). When constructing an Unknown object, neither Fish nor Bird will call the Animal constructor. Unknown will call the constructor for the Animal virtual base.
Vals are initialized in the order they are declared (well, precisely, non-lazy vals are), so properties is getting initialized before loadedProps. Or in other words, loadedProps is still null when propertiesis getting initialized. The simplest solution here is to define loadedProps before properties: class Config { private val loadedProps = { val p = new … Read more
Hence does it mean that even if a constructor completes running without any exception, there is no guarantee whether an object is created? Simply speaking, a constructor does not create an object. It just initializes the state of the object. It’s the new operator which creates the object. Now, let’s understand this in little detail. … Read more
There are two good ways to do this. Which is best depends on the specific circumstance. The first is reflection: (clojure.lang.Reflector/invokeConstructor (resolve (symbol “Integer”)) (to-array [“16”])) That’s like calling (new Integer “16”) …include any other ctor arguments you need in the to-array vector. This is easy, but slower at runtime than using new with sufficient … Read more
The copy constructor doesn’t (can’t) really make a copy of the object because Derived::Derived(const Derived&) can’t access pdata to change it. Sure it can: Derived(const Derived& d) : Base(d) { cout << “Derived::Derived(const B&)” << endl; } If you don’t specify a base class constructor in the initializer list, its default constructor is called. If … Read more
You can’t do it by default with Laravel 5.3. But when you edit you Kernel.php and change protected $middleware = []; to the following it wil work. protected $middleware = [ \Illuminate\Foundation\Http\Middleware\CheckForMaintenanceMode::class, \Illuminate\Session\Middleware\StartSession::class, \Illuminate\View\Middleware\ShareErrorsFromSession::class, ]; protected $middlewareGroups = [ ‘web’ => [ \App\Http\Middleware\EncryptCookies::class, \Illuminate\Cookie\Middleware\AddQueuedCookiesToResponse::class, \App\Http\Middleware\VerifyCsrfToken::class, \Illuminate\Routing\Middleware\SubstituteBindings::class, ], ‘api’ => [ ‘throttle:60,1’, ‘bindings’, ], ]; Hope … Read more
It’s not legal to have a struct that contains itself as a member. This is because a struct has fixed size, and it must be at least as large as the sum of the sizes of each of its members. Your type would have to have 8 bytes for the two floats, at least one … Read more